Generously grease a 13x9 baking pan or coat with nonstick spray.
In a medium bowl, thoroughly stir together the flour, sugar, and salt.
Using fork, a pastry blender, or fingertips, cut in butter until the mixture is the onsidtency of fine meal.
Sprinkle the cream over the flour mixture. Lightly stir to mix. Gently knead until the mixture hold together. If necessary, add up to 3 tsps more cream until the mixture holds together but it is not wet.
Alternatively, in a food processor, process the dry ingredients and the butter in an off/on butter in pulses until mixture is similiar to coarse meals, do not over process.add 1 Tbsp cream, a little at a time and process in off/on pulses until mixtue begins to hold together; add just enough more cream so the mixture hold together is not wet.
Firmly press the dough in an even layer into the baking pan.
Refrigerate for 30 minutes.
Preheat oven to 350°.
Bake in the middle of the oven for 10 minutes or just tinged with brown at the edges. Transfer the pan to a wire rack and let stand until cooled to room temperature about 5 minutes.
Spread pecans in a medium baking pan.
Combine the butter, brown sugar, salt, corn syrup and cream.
Bring to a boil over medium heat and cook, stirring occasionally for 4 minutes.
Remove from the heat, stir in the vanilla and 2 1/4 cups of the pecans.
Sspread topping evenly over the crust.
Bake in the middle of the oven for 20-24 minutes or until the topping is bubbly, golden brown and just slightly darker at the edges.
Transfer the pan to a wire rack and let stand until cooled to warm. Sprinkle the chocolate morsels evenly over the top.
Let stand until the morsels melt, then using a table knife, spread melted chocolate over the topping. It will not completely cover the topping, sprinkle the remaining 3/4 cup of pecans over the chocolate.
Let stand until cooled to barely warm.
Using a sharp knife, cut the slab into 32 bars, wipe knife clean between cuts.
Let stand until completely cooled.
Store in an airtight container for up to 2 weeks or freeze for up to 2 months.
If freezing, leave the slab whole, then cut into bars when partially thawed.